Japanese Patent Application Laid-Open Publication No. H02-297949 (Patent Document 1) describes a wire bonding method of applying a load and an ultrasonic wave to a bonding tool in a process of connecting a metal wire to an electrode pad of a semiconductor chip.
In addition, Japanese Patent Application Laid-Open Publication No. H07-58142 (Patent Document 2) describes a wire bonding device applying ultrasonic vibration in thermocompression wire bonding.